1. Field of the Invention
The present invention is related to the field of water sports, and more specifically to watercraft of the type towed behind a boat or other vessel.
2. Description of the Related Art
A fun water sport is to be towed behind a boat on an innertube, that is also known as a ski biscuit. A rider sits in the innertube, which is attached to a speeding boat by a towline, and thus gets pulled wherever the boat goes.
A problem with this sport is that the rider lacks control over where the innertube goes. Every time the boat turns, the innertube tends to continue in its original direction, unless pulled in a different direction. A large body of water is required to make turns safely at high-speed. If such is not the case, the innertube might approach the shore, or undesirable debris. In addition, this sport remains unchallenging compared to similar water sports, where the rider can steer.
There has been some interest in making steerable innertubes. For example, in U.S. Pat. No. 5,819,680, a steerable towcraft is taught. The floating device is triangular, which does not make it exactly a ski biscuit. The rider can pull on a steering line with respect to the towline, which rotates the floating device. A fin that is fixedly attached to the underside of the floating device converts the rotation into changed direction.
A problem in this invention is that steering can be performed only when there is active towing by the boat, i.e. with the towline being taut. When the towline is slack, there is no steering control. Plus, it is not adaptable to existing ski biscuits.
Moreover, as per U.S. Pat. No. 5,899,782 to Martin, a flotation device is provided that can be towed behind a speeding boat, and can change direction. The rider pulls on handle with respect to the taut towline, which rotates the flotation device with respect to the direction that it is being pulled. Again, a fin-like apparatus provided under the flotation device converts this rotation into a changed direction of motion for the flotation device.
This invention has the same problem of lack of steering control when the towline is not taut. In addition, the handle may fall into the water, in which case the rider loses control.